Voice prosthesis

ABSTRACT

A voice prosthesis to be mounted in a fistula between trachea and esophagus comprises a spool-shaped element with a through passage and a valve mechanism controlling the connection through said passage and having sealing surfaces which can be pressed against each other, means being provided to produce a magnet force acting between the sealing surfaces to keep said surfaces pressed against each other in the closed position of the valve mechanism.

FIELD OF THE INVENTION

The invention relates to a voice prosthesis to be mounted in a fistulabetween trachea and esophagus, comprising a spool-shaped element havinga through passage and a valve mechanism controlling the connectionthrough said passage, said valve mechanism having sealing surfaces whichcan be pressed against each other.

BACKGROUND OF THE INVENTION

When a person's larynx has been removed by surgery due to pathologicalchanges in the throat, the trachea is sutured to an opening in thethroat (tracheostoma). By the surgery the person has lost the ability tospeak, and in order to restore this ability a method has been appliedfor several years, in a voice prosthesis of the kind referred to aboveis mounted in a fistula, i.e. a passage between trachea and esophagus.At speech the tracheostoma is occluded by sealing the same either by thepatient placing the fingers against the tracheostoma or by thetracheostoma being closed by an in connection therewith provided stomavalve. Then, the expiration air is pressed from the lungs through thevoice prosthesis into esophagus where the mucous membranes of the throatare brought into vibration and speech is produced as a consequencethereof. Several voice prosthesis are described in U.S. Pat. No.4,911,716, U.S. Pat. No. 4,435,853, U.S. Pat. No. 4,820,304, andDD-Al-275 183. The voice prosthesis is fixed in the fistula by means oftwo flanges on the spool-shaped element or by means of a flange andribbons. The spool-shaped element can be cylindrical or oval andpreferably it is made of silicon rubber. All existing voice prostheseshave in common that they provide a check valve function, which meansthat the valve mechanism normally is closed but opens when air ispressed from trachea via the valve to esophagus. The valve mechanism ismaintained in the closed position by spring bias which in most cases ismaintained by elasticity of the material from which the voice prosthesisis made.

When existing voice prostheses are mounted in the fistula the functionis acceptable initially but they have a non-acceptably short liferanging from a week up to two years. There are two reasons for thisshort life, viz.

-   -   1) Growth of fungus, candida, will cover the sealing surfaces of        the valve mechanism, which causes leakage at the intake of        beverages and is the primary reason for exchange of the voice        prosthesis.    -   2) Fatigue of the spring bias (the material of the voice        prosthesis) so that the valve as a consequence thereof will be        partly open in the normal position causing leakage through the        voice prosthesis.

A further drawback adds to these drawbacks viz. that the spring biaswhich shall maintain the valve mechanism closed in the normal positionincreases with the opening movement of the valve mechanism so that aconsiderably increased air resistance will be obtained as a consequencethereof at increased air flow, which means that the patient will berestrained from producing a more powerful speech or in any case cannotproduce such speech without great effort, which makes the speechstrenuous.

In existing voice prostheses the valve mechanism opens relativelyquickly and preferably at low pressure when air with the stoma closed ispressed against the valve mechanism. Then, when the air flow isincreased at speech the flow resistance will quickly be increased asmentioned above.

It is known per se to provide a valve mechanism with a permanent magnetfunction in order to maintain the valve mechanism in closed condition.Thus, there is disclosed in WO 93/11820 a cough valve having a valveflap which is kept in closed position against a seat by the force of apermanent magnet, such force acting between the valve flap and the seat,in order to be opened at a rising high overpressure in trachea such asat an attack of coughing. It is thus the question of a pure safety valvewherein the permanent magnet function is utilized for a completely otherpurpose than for overcoming the drawbacks connected with existing voiceprostheses, which have been discussed above and which are not at allmentioned in WO 93/11820.

As mentioned above the growth of candida on the sealing surfaces of thevoice prosthesis is the main reason for the necessity of exchanging thevoice prosthesis. It is well known that the candida fungus affectssilicon rubber which is the material almost exclusively used in voiceprostheses, and above all at such places which are in contact with themucous membranes in the throat.

SUMMARY OF THE INVENTION

The present invention provides a voice prosthesis comprising aspool-shaped hollow body for insertion into a fistula in atracheoesophageal wall of a patient. Such body having an open trachealend an open esophageal end. A first retention flange is disposed at thetracheal end of the body. A second retention flange is disposed at theesophageal end of the body. Such body defining a through passage betweenthe tracheal end and the esophageal end. A valve seat is formed by thebody at the esophageal end thereof. A valve flap cooperates with suchvalve seat to control air flow through the through passage of such body.The valve flap occludes air flow through such through passage in aclosed position of the valve flap against the valve seat. A magnet isdisposed on one of such valve flap and such valve seat. A magneticallyattracted material is disposed on an opposed one of such valve flap andsuch valve seat. The magnet and the magnetically attracted materialprovide a magnet force between the valve flap and the valve seat in theclosed position of the valve flap. Seating surfaces are formed by suchvalve flap and such valve seat, respectively, to be pressed against eachother by a magnetic force in such closed position. The magnet forcenormally maintaining such valve flap in sealing engagement with thevalve seat in such closed position to be disengaged therefrom by anoverpressure in trachea overcoming such magnet force.

OBJECTS OF THE INVENTION

It is, therefore, one of the primary objects of the present invention toprovide a voice prosthesis will utilize a higher initial pressure atspeech in order to provide a reduced closing force with greater air flowonce the valve mechanism has opened.

Another object of the present invention is to provide a voice prosthesiswhich is candida resistant.

These and various other objects and advantages of the present inventionwill become more readily apparent to those persons skilled in the artfrom the following more detailed description of the invention,particularly, when such description is taken in conjunction with theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation view partially in cross-section illustratingone embodiment of the present invention;

FIG. 2 is a side elevation view partially in cross-section illustratinganother embodiment of the present invention;

FIG. 3 is a side elevation view partially in cross-section illustratingstill another embodiment of the present invention;

FIG. 4 is a side elevation view partially in cross-section illustratingyet another embodiment of the present invention;

FIG. 5 is a side elevation view partially in cross-section illustratinga further embodiment of the present invention;

FIG. 6 is a side elevation view partially in cross-section illustratingan additional embodiment of the present invention;

FIG. 7 is a side elevation view partially in cross-section illustratinga presently preferred embodiment of the present invention;

FIG. 8 is a side elevation view partially in cross-section illustratinganother embodiment of the present invention; and

FIG. 9 is a side elevation view partially in cross-section illustratingstill another embodiment of the present invention.

BRIEF DESCRIPTION OF THE PRESENTLY PREFERRED AND VARIOUS ALTERNATIVEEMBODIMENTS OF THE INVENTION

For a better understanding of the present invention reference is nowmade more particularly to the drawings.

When the magnet function is utilized in order to maintain the voiceprosthesis in closed position, as in the voice prosthesis according tothe present invention, the portions sealing against each other in thevalve mechanism can consist of, or be coated with, a hard candidaresistant material, for example PVDE, polypropylene or polyethylene,which, however, in existing voice prostheses rather quickly would resultin beginning leakage at beginning fatigue of the silicon rubber theelasticity of which produces the closing force, because an increasedcompression force is required in order to seal between two hard surfacesthan between two soft surfaces. A reduced compression force cannot pushaway food surface thereof to be engaged with the seat is provided with aplate 19 of candida resistant material or is coated with such amaterial.

A permenent magnet 20 is provided in the valve flap and is connectedwith the flap by gluing or by being moulded into the material atinjection moulding of the valve flap. Seat 15 should be made of amagnetically attractable material so that the valve flap by magneticforce normally is held in closed position sealingly engaging the seatbut can be lifted momentarily from the seat by an overpressure intrachea overcoming the magnet force. Lining 14 or at least that partthereof which forms seat 15 preferably consists of magnetic stainlesssteel. In a modification of the embodiment shown the magnet or severalmagnets are provided in seat 15 and a plate 19 is made of a magneticallyattractable material such as magnetic stainless steel. Shield 16protects the valve mechanism against candida attack. In order that thepermanent magnet 20 shall be protected against corrosion it can becoated with a corrosion resistant material.

FIG. 2 discloses a modification of the embodiment in FIG. 3 wherein theseat comprises a flat ring 21. In this case valve flap 18 as well asseat ring 21 are provided with a permanent magnet 20 and 20′,respectively. Alternatively, only either plate 19 on the valve flap orseat ring 21 is provided with magnet and the seat ring and the plate,respectively, is made of a magnetically attractable material.

The embodiment shown in FIG. 3 principally is constructed in the sameway as the embodiment in FIG. 1 but valve flap 18 has been replaced by avalve element formed as a ball 22 which is supported by a strip 23 madeintegral with flange 12 and allowing ball 22 to be lifted from seat 15under elastic yielding. Ball 22 is provided with one or more permanentmagnets 20 in order to be held by magnet force in engagement with seat15 consisting of a magnetically attractable material. Alternatively ball22 in its entirety can comprise a permanent magnet, or one or morepermanent magnets can be provided in the seat to attract ball 22 whichin that case is made in its entirety of a magnetically attractablematerial.

The embodiment in FIG. 4 is slightly different from the embodimentpreviously described because the valve mechanism is of the type “duckbill”. It is formed by a slotted extension 10′ of the spool-shapedelement 10, projecting from flange 12. The slot is indicated at 24 andis defined by surfaces having a coating 25 of candida resistantmaterial. The two halves of extension 10′ formed by the slot aremutually attracted by two permanent magnets 20 one on each of said twohalves, in order that the slot, i.e. the valve mechanism shall be keptclosed. At overpressure in trachea acting in passage 11 the magnet forcewill be overcome and slot 24 will be opened under elastic separation ofthe two halves of extension 10′ so that a connection through passage 11will be established. Instead of the two halves of extension 10′ beingprovided with a magnet, only one of said halves can have a magnet andthe other one can have a block of magnetically attractable materialco-operating with the magnet.

In the embodiment according to FIG. 5 lining 14 made of candidaresistant material forms seat 15 in passage 11 said seat forming radialarms 26 supporting a guide 27 for a stem 28 on a disk valve 29co-operating with seat 15. Disc valve 29 is provided with one or morepermanent magnets 20, and for co-operation with the magnet or themagnets, respectively, guide 27 is partly made of a magneticallyattractable material 30 so that disc valve 29 is kept in engagement withseat 15 by magnet force. At overpressure in passage 11 which actsagainst disc valve 29 this is lifted from seat 15 the magnet force beingovercome, so that a connection is established through passage 11. In amodification of this embodiment the guide is provided with a permanentmagnet and the disc valve is provided with or is made of a magneticallyattractable material. Preferably, disc valve is made of a candidaresistant material in its. entirety.

FIG. 6 discloses an embodiment in accordance with FIG. 1 wherein thepermanent magnet, however, is replaced by an electromagnet. A wirewinding 31 is embedded into lining 14 and has connection wires 32 forconnection of the winding to an electric power source. The lining andthus the seat in this case should consist of a magnetizable material tobe magnetized at energization and thus attract plate 19 on valve flap 18said plate consisting of a magnetically attractable material.

In FIG. 7 the embodiment of the voice prosthesis according to theinvention presently preferred is disclosed said embodiment being amodification of the embodiment in FIG. 1 as is the embodiment in FIG. 2.In this embodiment the voice prosthesis comprises a spool-shaped element10 of silicon rubber having a distal outside flange 12 and a proximaloutside flange 13 said latter flange being shown with a “tail” or strap33 (fragmentarily shown) having a suitable length. This strap can beused in handling the voice prosthesis when it shall be mounted in ordemounted from the fistula and also can serve as anchoring means foranchoring the voice prosthesis on an insertion instrument. Thespool-shaped element in this embodiment forms an obliquely bevelledextension 34 at the distal end. When the voice prosthesis is positionedin the fistula said portion extends into esophagus and prevents liquidand food passing down through esophagus from entering passage 11 in thespool-shaped element and from disturbing the function of the voiceprosthesis. A lining 14 of a candida resistant and magneticallyattractable material, e.g. magnetic stainless steel is inserted into thepassage, and said lining at the distal end forms the annular seat 15 ofthe voice prosthesis. The lining can be attached by vulcanization orgluing to the spool-shaped element.

The valve flap 18 of the voice prosthesis, which cooperates with seat 15consists of hard plastics and forms a cavity 35 in which a permanentmagnet 20 is located and is retained therein by means of a glue layer 36in the cavity, extending over the magnet. Valve flap 18 is articulatelyI connected with the spool-shaped element 10 by means of a portion 37which is injection moulded integrally with the spool-shaped element inanother cavity 38 in valve flap 18 and at a web 17 provided as a jointconnects to the rest of element 10, a pin 39 on the valve flap beingsurrounded by; portion 37 for locking said portion on the valve flap.

In this embodiment the lining can be made of plastics and can have atthe distal end thereof a permanent magnet moulded or glued into thelining. By this arrangement the risk of the lining eventually beingmagnetized by magnet 20 is avoided. By such magnetization the magneticretainment of the valve flap in closed position may be uncontrollablystrong and may require an opening pressure which is too high.

In the embodiment according to FIG. 8 valve flap 18 consisting of hardplastics with a magnet 20 moulded there into is connected by means of apivot 41 with a hinge

flange 42 of hard plastics which is attached by vulcanization to thespool-shaped element and is kept engaged with the outside surface oflining 14 which can consist of a magnetically attractable material suchas stainless steel, or can be made of plastics with a built-in permanentmagnet for co-operation with magnet 20.

In FIG. 9 hinge flange 42 is made as an integral portion of a ring 43 ofhard plastics, which forms seat 15 and is attached to the spool-shapedelement 10 by vulcanization and which engages lining 14 inserted intosaid element.

Also in this case the lining can consist of stainless steel or plasticswith a built-in permanent magnet in order to keep the valve flap againstseat 15 in cooperation with magnet 20 moulded into the valve flap. Thespool-shaped element in this case has an obliquely bevelled extension 34with a permanent magnet 44 moulded there into, which has such polarityin relation to magnet 20 that it repels this magnet and thus the flap sothat this cannot be left in open position.

Lining 14 in the several embodiments of the voice prosthesis accordingto the invention can be attached to he spool-shaped element 10 byvulcanization or gluing, but it is also possible to provide as analternative or complement; a mechanical attachment by the lining beingpushed into passage 11 and under elastic yielding of the spool-shapedelement snaps into positive engagement with said element at shoulders onthe outside surface of the lining and inside the passage.

Instead of the lining being made of stainless steel in the embodimentsaccording to FIGS. 1 and 3 and 7 to 9 it can be made of hard plasticswith one or more permanent magnets moulded thereinto for co-operationwith the magnet in the valve flap.

1. A voice prosthesis comprising: a spool-shaped hollow body forinsertion into a fistula in a tracheoesophageal wall of a patient, saidbody having an open tracheal end an open esophageal end; a firstretention flange at said tracheal end of said body; a second retentionflange at said esophageal end of said body, said body defining a throughpassage between said tracheal end and said esophageal end; a valve seatformed by said body at said esophageal end thereof; a valve flapcooperating with said valve seat to control air flow through saidthrough passage of said body, said valve flap occluding air flow throughsaid through passage in a closed position of said valve flap againstsaid valve seat; a permanently magnetically attracted material disposedon an opposed one of said valve flap and said valve seat, said magnetand said magnetically attracted material providing a magnet forcebetween said valve flap and said valve seat in said closed position ofsaid valve flap; and a permanent magnet on one of the valve flap andvalve seat, providing a permanent magnetic force on said permanentlymagnetically attracted material; seating surfaces formed by said valveflap and said valve seat, respectively, to be pressed against each otherby a magnetic force in said closed position, said magnet force normallymaintaining said valve flap in sealing engagement with said valve seatin said closed position to be disengaged therefrom by an overpressure intrachea overcoming said magnet force.
 2. A voice prosthesis, accordingto claim 1, wherein said at least one of said magnet and saidmagnetically attracted material is a permanent magnet.
 3. A voiceprosthesis, according to claim 2, wherein said magnet is a permanentmagnet.
 4. A voice prosthesis, according to claim 1, wherein said atleast one of said magnet and said magnetically attracted material is anelectromagnet.
 5. A voice prosthesis, according to claim 4, wherein saidmagnet is an electromagnet.
 6. A voice prosthesis, according to claim 1,wherein said at least one of said magnet and said magnetically attractedmaterial are secured by gluing.
 7. A voice prosthesis, according toclaim 1, wherein said at least one of said magnet and said magneticallyattracted material are secured by molding.
 8. A voice prosthesis,according to claim 1, wherein said at least one of said magnet and saidmagnetically attracted material are coated with a surface layer of acorrosion resistant material.
 9. A voice prosthesis, according to claim1, wherein at least one of said sealing surfaces is a candida resistantmaterial.
 10. A voice prosthesis, according to claim 9, wherein onesealing surface of said candida resistant material is formed as a valveseat which extends axially on at least one side of said valve seat as alining of said through passage in said spool-shaped hollow body.